Hi guys.

I'm just curious to know what the deal is with depression and falling in love/romance.
I know that depression generally can dampen positive emotions - love, desire, romance.
Currently I'm in a long distance relationship, my boyfriend is dealing with a very difficult life situation on the other side of the world, we talk everyday, but we miss each other terribly. He has started to feel very depressed. This is situational depression, so I'm guessing it will pass once the circumstances he is struggling with are resolved.
But I'm a little concerned. He loves me very much, I know this beyond doubt. However there has been a change lately as he has started to feel increasingly depressed about his situation. I used to make him so happy, I could see how much of a boost I gave him, I put that spring into his step and he was happier. We are still in the early stages of our relationship, only five months into it. I understand completely that his feelings have nothing to do with a decreased love or desire for me, he tells me this all the time. He says he misses me terribly and finds what he's having to deal with all on his own so hard.
My concern is will his depression eventually effect the way he feels toward me? I have heard that depressed people can feel that they have 'fallen out of love' with their partners/spouses, when in fact it is just the depression. I love him very much, and we both know we have found something special. It would be such a shame if depression were to suck the love from between us.
Am I worrying for no reason or is my concern valid? Could anyone who has expereinced a new relationship while depressed please give me an indication of how much effect it has on their love? I miss him too terribly, but I don't feel depressed like he does. Though I miss him so much, I just have to think of him and I feel a warm happy glow radiating out from within me. He is still my happy thought, even though he is on the other side of the world and missing him hurts.
Should I be worried if he is not feeling the same happiness? Are there any suggestions for what I could do to help him, or just continue to be supportive and positive, and hope that it passes soon?

Thanks